<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<style type="text/css">
    body,
    html {
        margin: 0;
        width: 100%;
        overflow: hidden;
        background: #000000;
    }
    
    canvas {
        position: absolute;
        width: 100%;
    }
    
    .control {
        position: absolute;
    }
    
    .control input {
        border: 0;
        margin: 0;
        padding: 15px;
        outline: none;
        text-align: center;
    }
    
    .control button {
        border: 0;
        margin: 0;
        padding: 15px;
        outline: none;
        background: #333;
        color: #fff;
    }
    
    .control button:focus,
    .control button:hover {
        background: #222
    }
</style>
<script src="js/jquery.min.js" type="text/javascript" charset="utf-8"></script>

<body>
    <div class="control" style="position:absolute">
    </div>
</body>
<script type="text/javascript">
    var can = document.createElement("canvas");
    document.body.appendChild(can);
    var ctx = can.getContext('2d');
    var Fireworks = function() {
        var self = this;
        var rand = function(rMi, rMa) {
            return ~~((Math.random() * (rMa - rMi + 1)) + rMi);
        }
        var hitTest = function(x1, y1, w1, h1, x2, y2, w2, h2) {
            return !(x1 + w1 < x2 || x2 + w2 < x1 || y1 + h1 < y2 || y2 + h2 < y1);
        };
        self.init = function() {
            self.canvas = document.createElement('canvas');
            self.canvas.width = self.cw = $(window).innerWidth();
            self.canvas.height = self.ch = $(window).innerHeight();
            self.particles = [];
            self.partCount = 150;
            self.fireworks = [];
            self.mx = self.cw / 2;
            self.my = self.ch / 2;
            self.currentHue = 30;
            self.partSpeed = 5;
            self.partSpeedVariance = 10;
            self.partWind = 50;
            self.partFriction = 5;
            self.partGravity = 1;
            self.hueMin = 0;
            self.hueMax = 360;
            self.fworkSpeed = 4;
            self.fworkAccel = 10;
            self.hueVariance = 30;
            self.flickerDensity = 25;
            self.showShockwave = true;
            self.showTarget = false;
            self.clearAlpha = 25;
            $(document.body).append(self.canvas);
            self.ctx = self.canvas.getContext('2d');
            self.ctx.lineCap = 'round';
            self.ctx.lineJoin = 'round';
            self.lineWidth = 1;
            self.bindEvents();
            self.canvasLoop();
            self.canvas.onselectstart = function() {
                return false;
            };
        };
        self.createFireworks = function(startX, startY, targetX, targetY) {
            var newFirework = {
                x: startX,
                y: startY,
                startX: startX,
                startY: startY,
                hitX: false,
                hitY: false,
                coordLast: [{
                    x: startX,
                    y: startY
                }, {
                    x: startX,
                    y: startY
                }, {
                    x: startX,
                    y: startY
                }],
                targetX: targetX,
                targetY: targetY,
                speed: self.fworkSpeed,
                angle: Math.atan2(targetY - startY, targetX - startX),
                shockwaveAngle: Math.atan2(targetY - startY, targetX - startX) + (90 * (Math.PI / 180)),
                acceleration: self.fworkAccel / 100,
                hue: self.currentHue,
                brightness: rand(50, 80),
                alpha: rand(50, 100) / 100,
                lineWidth: self.lineWidth
            };
            self.fireworks.push(newFirework);
        };
        self.canvasLoop = function() {
            window.requestAnimationFrame(self.canvasLoop, self.canvas);
            self.ctx.globalCompositeOperation = 'destination-out';
            self.ctx.fillStyle = 'rgba(0,0,0,' + self.clearAlpha / 100 + ')';
            self.ctx.fillRect(0, 0, self.cw, self.ch);
            self.updateFireworks();
            self.updateParticles();
            self.drawFireworks();
            self.drawParticles();
        };
        self.drawParticles = function() {
            var i = self.particles.length;
            while (i--) {
                var p = self.particles[i];
                var coordRand = (rand(1, 3) - 1);
                self.ctx.beginPath();
                self.ctx.moveTo(Math.round(p.coordLast[coordRand].x), Math.round(p.coordLast[coordRand].y));
                self.ctx.lineTo(Math.round(p.x), Math.round(p.y));
                self.ctx.closePath();
                self.ctx.strokeStyle = 'hsla(' + p.hue + ', 100%, ' + p.brightness + '%, ' + p.alpha + ')';
                self.ctx.stroke();
                if (self.flickerDensity > 0) {
                    var inverseDensity = 50 - self.flickerDensity;
                    if (rand(0, inverseDensity) === inverseDensity) {
                        self.ctx.beginPath();
                        self.ctx.arc(Math.round(p.x), Math.round(p.y), rand(p.lineWidth, p.lineWidth + 3) / 2, 0, Math.PI * 2, false)
                        self.ctx.closePath();
                        var randAlpha = rand(50, 100) / 100;
                        self.ctx.fillStyle = 'hsla(' + p.hue + ', 100%, ' + p.brightness + '%, ' + randAlpha + ')';
                        self.ctx.fill();
                    }
                }
            };
        };
        self.drawFireworks = function() {
            var i = self.fireworks.length;
            self.ctx.globalCompositeOperation = 'lighter';
            while (i--) {
                var f = self.fireworks[i];
                self.ctx.lineWidth = f.lineWidth;
                var coordRand = (rand(1, 3) - 1);
                self.ctx.beginPath();
                self.ctx.moveTo(Math.round(f.coordLast[coordRand].x), Math.round(f.coordLast[coordRand].y));
                self.ctx.lineTo(Math.round(f.x), Math.round(f.y));
                self.ctx.closePath();
                self.ctx.strokeStyle = 'hsla(' + f.hue + ', 100%, ' + f.brightness + '%, ' + f.alpha + ')';
                self.ctx.stroke();
                if (self.showTarget) {
                    self.ctx.save();
                    self.ctx.beginPath();
                    self.ctx.arc(Math.round(f.targetX), Math.round(f.targetY), rand(1, 8), 0, Math.PI * 2, false)
                    self.ctx.closePath();
                    self.ctx.lineWidth = 1;
                    self.ctx.stroke();
                    self.ctx.restore();
                }
                if (self.showShockwave) {
                    self.ctx.save();
                    self.ctx.translate(Math.round(f.x), Math.round(f.y));
                    self.ctx.rotate(f.shockwaveAngle);
                    self.ctx.beginPath();
                    self.ctx.arc(0, 0, 1 * (f.speed / 5), 0, Math.PI, true);
                    self.ctx.strokeStyle = 'hsla(' + f.hue + ', 100%, ' + f.brightness + '%, ' + rand(25, 60) / 100 + ')';
                    self.ctx.lineWidth = f.lineWidth;
                    self.ctx.stroke();
                    self.ctx.restore();
                }
            };
        };
        self.updateFireworks = function() {
            var i = self.fireworks.length;
            while (i--) {
                var f = self.fireworks[i];
                self.ctx.lineWidth = f.lineWidth;
                vx = Math.cos(f.angle) * f.speed,
                    vy = Math.sin(f.angle) * f.speed;
                f.speed *= 1 + f.acceleration;
                f.coordLast[2].x = f.coordLast[1].x;
                f.coordLast[2].y = f.coordLast[1].y;
                f.coordLast[1].x = f.coordLast[0].x;
                f.coordLast[1].y = f.coordLast[0].y;
                f.coordLast[0].x = f.x;
                f.coordLast[0].y = f.y;
                if (f.startX >= f.targetX) {
                    if (f.x + vx <= f.targetX) {
                        f.x = f.targetX;
                        f.hitX = true;
                    } else {
                        f.x += vx;
                    }
                } else {
                    if (f.x + vx >= f.targetX) {
                        f.x = f.targetX;
                        f.hitX = true;
                    } else {
                        f.x += vx;
                    }
                }
                if (f.startY >= f.targetY) {
                    if (f.y + vy <= f.targetY) {
                        f.y = f.targetY;
                        f.hitY = true;
                    } else {
                        f.y += vy;
                    }
                } else {
                    if (f.y + vy >= f.targetY) {
                        f.y = f.targetY;
                        f.hitY = true;
                    } else {
                        f.y += vy;
                    }
                }
                if (f.hitX && f.hitY) {
                    self.createParticles(f.targetX, f.targetY, f.hue);
                    self.fireworks.splice(i, 1);
                }
            };
        };
        self.createParticles = function(x, y, hue) {
            var countdown = self.partCount;
            while (countdown--) {
                var newParticle = {
                    x: x,
                    y: y,
                    coordLast: [{
                        x: x,
                        y: y
                    }, {
                        x: x,
                        y: y
                    }, {
                        x: x,
                        y: y
                    }],
                    angle: rand(0, 360),
                    speed: rand(((self.partSpeed - self.partSpeedVariance) <= 0) ? 1 : self.partSpeed - self.partSpeedVariance, (self.partSpeed + self.partSpeedVariance)),
                    friction: 1 - self.partFriction / 100,
                    gravity: self.partGravity / 2,
                    hue: rand(hue - self.hueVariance, hue + self.hueVariance),
                    brightness: rand(50, 80),
                    alpha: rand(40, 100) / 100,
                    decay: rand(10, 50) / 1000,
                    wind: (rand(0, self.partWind) - (self.partWind / 2)) / 25,
                    lineWidth: self.lineWidth
                };
                self.particles.push(newParticle);
            }
        };
        self.updateParticles = function() {
            var i = self.particles.length;
            while (i--) {
                var p = self.particles[i];
                var radians = p.angle * Math.PI / 180;
                var vx = Math.cos(radians) * p.speed;
                var vy = Math.sin(radians) * p.speed;
                p.speed *= p.friction;
                p.coordLast[2].x = p.coordLast[1].x;
                p.coordLast[2].y = p.coordLast[1].y;
                p.coordLast[1].x = p.coordLast[0].x;
                p.coordLast[1].y = p.coordLast[0].y;
                p.coordLast[0].x = p.x;
                p.coordLast[0].y = p.y;
                p.x += vx;
                p.y += vy;
                p.y += p.gravity;
                p.angle += p.wind;
                p.alpha -= p.decay;
                if (!hitTest(0, 0, self.cw, self.ch, p.x - p.radius, p.y - p.radius, p.radius * 2, p.radius * 2) || p.alpha < .05) {
                    self.particles.splice(i, 1);
                }
            };
        };
        self.bindEvents = function() {
            $(self.canvas).on('mousedown', function(e) {
                self.mx = e.pageX - self.canvas.offsetLeft;
                self.my = e.pageY - self.canvas.offsetTop;
                self.currentHue = rand(self.hueMin, self.hueMax);
                self.createFireworks(self.cw / 2, self.ch, self.mx, self.my);
            });
            $(self.canvas).on('mouseup', function(e) {
                $(self.canvas).off('mousemove.fireworks');
            });
        };
        self.init();
    }

    function resize() {
        can.width = window.innerWidth;
        can.height = window.innerHeight;
    }
    const max_radius = 3;
    const min_radius = 1;
    //粒子大小
    const drag = 50;
    window.onresize = function() {
        resize();
    };

    function cfill() {
        ctx.fillStyle = "#000";
        ctx.fillRect(0, 0, can.width, can.height);
        ctx.fill();
    }
    resize();
    cfill();
    class Particle {
        constructor(pos, target, vel, color, radius) {
            this.pos = pos;
            this.target = target;
            this.vel = vel;
            this.color = color;
            this.radius = radius;
            this.direction = 0;
        }
        set(type, value) {
            this[type] = value;
        }

        update() {
            this.radius = 2;
            this.vel.x = (this.pos.x - this.target.x) / drag;
            this.vel.y = (this.pos.y - this.target.y) / drag;
            this.pos.x -= this.vel.x;
            this.pos.y -= this.vel.y;
        }
        draw() {
            ctx.beginPath();
            ctx.fillStyle = this.color;
            ctx.arc(this.pos.x, this.pos.y, this.radius, 0, Math.PI * 2);
            ctx.fill();
        }
    }
    var particles = [];
    var colors = ["#bf1337", "#f3f1f3", "#084c8d", "#f2d108", "#efd282"];
    var bool = true;
    var current = 0,
        i;

    function changeText(text) {
        var current = 0,
            temp, radius, color;
        ctx.fillStyle = "#fff";
        ctx.font = "160px 楷体";
        ctx.fillText(text, can.width * 0.5 - ctx.measureText(text).width * 0.5, can.height * 0.5 + 60);
        var data = ctx.getImageData(0, 0, can.width, can.height).data;
        cfill();
        for (i = 0; i < data.length; i += 12) {
            if (data[i] !== 0 && (Math.random() * 10) >= 8.8) {
                radius = max_radius - Math.random() * min_radius;
                temp = {
                    x: (i / 4) % can.width,
                    y: ((i / 4) / can.width)
                };
                color = colors[0];
                var p = new Particle(
                    temp, {
                        x: (i / 4) % can.width,
                        y: ((i / 4) / can.width)
                    }, {
                        x: 0,
                        y: 0
                    },
                    color,
                    radius);
                particles.push(p);
                ++current;
            }
        }
        particles.splice(current, particles.length - current);
    }

    function draw(obj) {
        ctx.beginPath();
        ctx.arc(obj.target.x, obj.target.y, obj.radius, 0, 2 * Math.PI);
        ctx.fillStyle = obj.color;
        ctx.fill();
    }
    changeText("  元旦快乐");
    var t = 0;
    var id;
    var fworks = new Fireworks();

    function init() {
        id = window.requestAnimationFrame(init)
        if (t >= particles.length - 1) {
            window.cancelAnimationFrame(id)
        }
        draw(particles[t])
        t++;
        var rand = function(rMi, rMa) {
            return ~~((Math.random() * (rMa - rMi + 1)) + rMi);
        }
        if (t % 5 == 0) {
            fworks.currentHue = rand(0, 360);
            fworks.createFireworks($(window).innerWidth() / 2, $(window).innerHeight(), particles[t].pos.x, particles[t].pos.y);
        }
    }
    init();
</script>

</html>